Interpretive Summary: Impatiens is currently among the most valuable and widely cultivated floriculture crops in the world. Although breeders need to select for highly floriferous cultivars, little consideration has been given to floral longevity as a means to increase the floriferousness of bedding crops. In this study, 259 commercial inbred lines of impatiens were evaluated for floral longevity as defined by the time between when a flower was completely open to when all of the petals abscised from the pedicle. Twelve inbreds (6 with high and 6 with low floral longevity) were selected and crossed in a half diallel to create 66 hybrids that were analyzed for flower longevity in 3 greenhouse environments. Significant general (GCA) and specific (SCA) combining abilities for floral longevity were detected, with GCA 37 times larger than SCA, indicating that additive genetic effects play a more important role in the inheritance of floral longevity in impatiens. This result indicates that there is good potential for breeding for floral longevity in impatiens and will be of interest to breeders of this important ornamental plant.

Technical Abstract:
Impatiens walleriana is currently among the most valuable and widely cultivated floriculture crops in the world. Highly floriferous cultivars are a primary goal for breeders of I. walleriana. Although breeders have selected for floriferousness, little consideration has been given to floral longevity as a means to increase the floriferousness of bedding crops. In this study, 259 commercial inbred lines of I. walleriana were evaluated for floral longevity as defined by the time between when a flower was completely open to when all of the petals abscised from the pedicle. Twelve inbreds (6 with high and 6 with low floral longevity) were selected and crossed in a half diallel to create 66 hybrids that were analyzed for flower longevity in 3 greenhouse environments. Significant general (GCA) and specific (SCA) combining abilities for floral longevity were detected. GCA mean squares were 36.6 times larger than the SCA mean squares, suggesting that additive genetic effects play a more important role in the inheritance of floral longevity in I. walleriana. This information, coupled with the significant amount of variation for floral longevity seen in the inbred population, indicates that there is good potential for breeding for floral longevity in I. walleriana to improve floriferousness of hybrids